Question

我的SQL查询返回结果如下：
我有两个表，Users和Category，其中Category使用User表中的外键（ userID ）（ id ）。

[ 
    { "userTime": "14:00",
        "id": 1,
        "name": "Jack",
        "Category.id": 11,
        "Category.name": "Category1",
        "Category.userID": 1
    },
    {
        "userTime": "14:00",
        "id": 1,
        "name": "Jack",
        "Category.id": 12,
        "Category.name": "Category2",
        "Category.userID": 1
    }   
]

但我想按如下方式显示结果：

        [
            {
                "userTime": "14:00",
                "id": 1,
                "name": "Jack",
                Category: [
                    {
                        id: 11,
                        name: "Category1",
                        userID: 1
                    },
                    {
                        id: 12,
                        name: "Category2",
                        userID: 1
                    }               
                ]
            }
        ]

我使用Tedious和Nodejs来查询SQL DB，如何通过使用nodejs或javascript来实现上述结果？

Answer 1

另一种方法是使用函数Array.prototype.reduce。

此方法使用变量group来放置必要的属性/键来构建分组键。

var array = [{      "userTime": "14:00",      "id": 1,      "name": "Jack",      "Category.id": 11,      "Category.name": "Category1",      "Category.userID": 1    },    {      "userTime": "14:00",      "id": 1,      "name": "Jack",      "Category.id": 12,      "Category.name": "Category2",      "Category.userID": 1    }  ],
    group = ['id'],
    result = Object.values(array.reduce((a, c) => {
      var key = group.map(g => c[g]).join('|');
      (a[key] || (a[key] = {userTime: c.userTime, id: c.id, name: c.name, Category: []})).Category.push({id: c['Category.id'], name: c['Category.name'], userID: c.id});    
      return a;
    }, {}));
  
console.log(result);

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在javascript中从SQL返回的连接结果

1 个答案: